In recent years, hot water vacuum extraction machines have come into vogue for permitting the housewife to clean rugs and floor surfaces by spraying a very hot water onto the surface by means of a spray nozzle fixed to a vacuum pick up head. The resulting dirty water is returned to a dirty water accumulation tank borne by the machine remote from the head and connected thereto by a suction hose leading from the tank to the vacuum head. In an effort to improve the cleaning action at the point of liquid spray application, such vacuum heads have employed electric motors driving a rotating brush or scrubber to aid in loosening of the dirt. Whether the surface being cleaned is a rug, or a solid flooring, removal of the dirt is effected by entraining the water within the air stream flowing through the connecting vacuum hose under vacuum pressure exerted at the dirty water accumulation tank.
Not only are there requirements to feed alternating current voltage to the electric drive motor for the scrubber, but due to the vacuum removal of dirty water through the vacuum hose, the electrical wires borne by the hose assembly must be maintained isolated from the water returning to the tank. Otherwise, the water will short the electrical wires with resulting damage to the assembly, if not to the scrubber drive motor. In addition, it must be appreciated that in the utilization of the hot water vacuum extraction machines, such vacuum hose assemblies are subjected to considerable mechanical abuse, the hoses are dragged over the surface being cleaned, they contact objects of furniture during cleaning, and they may be stepped on. This may not only impair their ability to carry the water during the vacuum return to the dirty water accumulation tank, but mechanical damage to the insulation surrounding the electrical wires, may, regardless of their possible contact with water, lead to shorting between the adjacent wires.
Such vacuum hose assemblies may be formed in a single or double concentric tube arrangement, with the tubes corrugated, tending to make them not only flexible but also permitting some expansion and contraction of the hose assembly. Due to the utilization of tubular couplings at respective ends of the hose assembly for coupling the hose assembly to the vacuum head at one end, and to the dirty water accumulation tank at the opposite end, electrical connection means must be attached to the lead wires. Male and female connectors electrically connect the leads borne by the hose assembly to the motor leads at the scrubber end of the vacuum hose and to the electrical supply means at the machine end. Where the hose assembly functions to return dirty water, means must be provided for prevention of any water from getting to the leads. Conventional single break connection and disconnection of the electrical leaks have in the past failed to insure against this possibility.
It is, therefore, a primary object of the present invention to provide an improved electrified vacuum hose for a wet pick up machine, in which electrical disconnection of the electrical wires leading from the machine proper to the scrubber motor of the pickup vacuum head, is assured, and wherein positive sealing of the electrical disconnect contacts is assured regardless of whether the electrical receptacle borne by the hose is in contact open or contact closed condition.